Liquid fuel combustion apparatus



T.'B. FOCKE LIQUID FUEL COMBUSTIO APPARATUS Nov. 2, 1943-.

Filed May'9, 1942 3 Sheets-Sheet l ha m uw E d A .QQ NQ ATTORN' 5 NOV. 2, 1943 T. B. FocKE j 2,333,473

LIQUID FUEL COMBUSTION APPARATUS Filed May 9, 1:942. 3 Sheets-Sheet 2 lLuoaooop/oonoooooooo'oo 96 95 .55

Q l ('lV-VENTOR.

BY aw www V .Aoge/VEYS,

Nov. 2, 1943. T. B, FOCK LIQUID FUEL COMBUSTION APPARATUS Filed May l9, 1942 3 VSheets-Sheet` 3 IN V EN TOR.

too much slr was admitted in the region of said y :,sssrzs sie as Fnsi. coUs'rroN Arr'rus ff-f E. Fe, @lowland Heights, Ghia, ns-

- signor to Perfection Stove Comp levelnnd,

of (this .oppression y e, rss2. serien No. esseci 8 :"efw 15s-91) This invention relates to improvements in liquid fuel burning apperetus oi the cl used for house heating or like purposes und ined by the inclusion of o burner howl; end its' mein ohiect is to provide epperetu's ci the nioresoid clees ond type that will operaie emciently end with s clesn lire throughout o wide ronge its lowest and highest rotes ci iuel conoption.

The present opplicetion is s. continuetion in port of one led by me on Mey il, leds, eriol l@ No. lel'li.

Burners of the referred to, prg my invention, operated sotisioctorily und eeiently only et s perticuler rete ol roel coption. When ultimetelyedopted ior use in iurnooes, is with automatic control systems. under certain conditions oi which the hurner wos required to operate for long peri ci time, sometimes for days end weeks, st very low or so-cslled pilot lire, these prior l typo burners proved to be inadequate because when opereting ot low fire combustion was poor and carbon iotion and deposit become excessive, frequently to the point of extinguishing the nre.

Further, these earlier burners were incopeble of consuming much more thon e. gallon of fuel per hourwhich is too little for house heating purposes under extreme couditiorvithout their having to be mode undhly large or else vrequiring the hosting of the bottom portion of the burner bowl for veporlnns purposes to such an extent that the life of the bowl was very limited. By ressort ci my invention, as will hereinafter more fully appear, l um ennhied to reisev the rate of oil consumption eppronimstely nity '35 percent without increasing the size of the burner bowl, and et the seme time keep the howl rele tively cool. i

A further defect or limitation in prior burners of the kind referred to, which rendered them no practical or unsatisfactory for the use to which my improved burner is espeoislly well edupted, was the loci; of s. proper balance between the secondary oir supply and the vapor vole et the 45 various stages within the required range oi opere,- ation. In these earlier burners, practically ell secondary air for all stages of operation was admitted through a single slot or lits equiveleht, o single series of holes, and es s, consequence, ier

slot or series of holes when the burner was operating at low re. This excess oi sir produced considerable turbulence within the burner bowl which interfered with proper mixing of the oil vapors end oir. This resulted in the excessive carbon formation et low re, hereinbefore mentioned.

it is e. further purpose of my invention, there fore, to eliminate the foregoing dimculties by positively separating the secondary air required for low nre from that required for high iirev whereby interference with low ilre operation by the secondery oir supply for higher fire purposes l is avoided. y

Another ohlect of the invention is to provide s. comretively smell howl-type burner that is cspsble oi e high rute oi oil consumption, and thst will function in .e thoroughly satisfactory manner with pructicelly complete combustionat all stages in s, relntively wide range of operation.

My improved burner is of such character that the primary end secondary air supplies outomatically adjust themselves to the diierent rotes of oil feed throughout o complete range of operation, thereby to maintain e. proper proportion of, or helence `between, the air and vapor volumes et all times, the oir apportionment being self-responsive to variations in vapor volume.

The foregoing objects and advantages, with others hereinafter appearing, are attained in the embodiments'oi the invention illustrated in the accompanying drawings wherein Fig. l is a, vertiq cal section through e. combustion apparatus incorporsting my improvements, the section being taken in oiiset planes as indicated by the line i-i of Fig. 2; Fig. 2 is e. plan view of the burner bowl assembly disconnected and removed from the bottom of the combustion chamber shown in Fig. l; Fig. 3 is o. sectional detail showing a. modifled form of the annuler element that defines the throat of the burner; Fig. d is n fragmentary plan. view of the seme; Fig. 5 is e. central vertical section, somewhat schematic in character, through a further modied form of the invention, and Fig.

6 is a. sectional plsn View of the apparatus shown in Fig. 5.

In the liquid fuel burning apparatus illustrated frogmenterily in Figs. 1 and 2, the burner bowl is designated generally by the reference numeral Land it comprisesan. annular top Wall 2, s, pe= ripheral well 3, and e bottom wall t. The top wall is formed with on inner horizontal portion o that is joined, through a shallow depending cylindrical portion t, to an outer frusto conical poro tion l, the lrino of which is flat and is welded or otherwise secured to the flanged upper edge of theperipheral woll 3. At equally spaced points about its circumference, the wall 2 is formed with boys 8 for the-purpose of increasing the radial dimension of the horizontal portion 5 at these points; and the shallow cylindrical portion 6 is provided with air admitting openings 9, said openings occurring one within each of the bays 8 and one between each two adjacent bays. The peripheral wall ofthe bowl is provided with three circumferential seriesA of perforations I0, II and I2.

Adjacent the front of the apparatus, the peits inner end to the burner bowl. The enlarged end 2'I of the plug 20 is notched at diametrically opposite points for the passage of projections or l rollers that extend inwardly from the sleeve 22, I one of such notches being shown at 23 in FiB. 1.

and the corresponding projection or roller at 24. The front edge of the enlargement of the plug is cut away on a. taper to one side of each of the notches thereby to provide 'a cam portion 2i for engagement with the corresponding projection or roller, these parts cooperating to press the plug inwardly so as to seal the joint between the gasket II and the flange I 6 when the plug is turned clockwise by means of its handle 2i.

The bottom wall 4 of the bowl is slightlydished, and at its center is provided with an opening in which is secured the lower end of an air tube 30 that is surmounted by an air distributor or nozzle 3i, the latter being shown as having perforations I2 in its top. Welded or otherwise secured to the exterior of the bottom wall 4 are insulating shields Il and I4, having central openings that align with the air tube 30; and liquid fuel is adapted to be delivered to the burner bowl through a supply pipe 3l that passes through openings in the shields 33 and 34 and in the wall 4, the pipe being welded or otherwise secured to said wall with a leak-proof joint.

Disposed above and in spaced, parallel relation to the horizontal portion 5 of the top wall 2 is a ring-like member 36 whose inner edge is flanged upwardly at 31. outwardly beyond an adjacent horizontal portion, said member dares upwardly at a slight angle and joins, through a vertical portion 38, a relatively wide horizontal peripheral flange 39. lIhe member 38 is rigidly secured to the top wall 2 by posts 40 of narrow and long cross-sectional shape, as indicated in Fig. 2, the posts being arranged with their longer cross sectional dimension radial to the bowl. This is for the purpose of minimizing resistance to the flow of air inwardly between the wail 2 and mell'ibel4 :i8 and for obviating voids of appreciable size in the air stream inwardly of the posts. The upper and lower ends of the posts 4l are prodesignated 4B, the element below said upstanding wall being iianged outwardly over the inner edge portion of the wall 2 to which it is secured, preferably by Welding. The upstanding wall is provided with a circumferential series of relatively closely spaced perforations or openings 41. while the frusto conical or generally outwardly and upwardly extending portion 45 is4 provided with an annular series of perforations or openings 48 shown as considerably larger than the openings 41 of the former series. It is the structure or element comprising the upstandng wall and the wall portion that extends generally outwardly and upwardly therefrom that constitutes the neck of the burner, said upstanding wall deiining the more restricted part or throat. In the present instance, the number of holes is the same in both series, but those designated 48 of the upper series are materially larger than the ones designated 41 of the lower series. It is the fact that the aggregate area or capacity of the perforations or openings in the generally outwardly and -upwardly extending portion of the structure that constitutes the neck of the burner is materially greater than the agregate area or capacity of the perforatlons or openings in the upstanding wall of said structure that characterizes or distinguishes the species of the invention ,to which the present continuation application is directed.

Surrounding the burner bowl is an air compartment 50 enclosed by a peripheral wail 5I, a circular bottom wall l2 and an annular top wall Il. This latter wall has its contracted up-.

per end ntted over and secured, as by welding, to the vertical portion 3i of the ring-like member 30. while its flared lower end terminates in a shallow cylindrical ilange that nts within the upper edge of the peripheral wall Il and is fastened thereto, as by screws 64. The bottom wall l2. apertured to accommodate the supply pipe Il, is provided with an opening 55, surrounded by a depending flange to which is connected an air duct 5l that leads from a suitable air impelling or supply means, such as a fan or blower.

The combustion chamber is enclosed by a .drum ll within the lower end of which is fitted any annular bottom wall B2, said wall extending from its flanged outer edge, where it is welded or otherwise fastened to the drum, generally downwardly and inwardly to a horizontal portion I3 whose inner edge is surrounded by a depending flange 64. When the burner bowl assembly is applied to the bottom wall of the combustion iected through slots in the member 3B and wall 2, respectively, and are fastened to said member and wall deslrably by welding. Y

An annular element 42, preferably of relatively thin steel having the quality to effectively withstand the heat to which it is. subjected, has its upper cylindrical end 44 fitted within the flanged edge 31 of the ring-like member 38, the parts being secured together as by welding. From its cylindrical end 44 the element converges downwardly in frusto conical form, as shown at 45. and joins a shallow vertical or upstanding wall chamber, the ilange 84 is received within the cylindrical portion 38 of the ring-like member 3,4, and the peripheral ange 39 of said member engages the underside of the horizontal portion 63 of the wall 62. Said peripheral flange and wall portion are provided with aligned openings (those of the ilange being designated 65 in Fig. 2) through which bolts 01 are downwardly projected v pplied to Liquid fuel from a suitable source is fed to the bowl I through a fuel feeding system of which the pipe 35 forms a part. The system includes means for varying the quantity of fuel delivered to the bowl for the purpose of producing diife'rent-sized lires from pilot to high. By means of an automatic control system, involving a socalled room thermostat, the lire may be regulated to maintain a given temperature within narrow limits in the generalvlcinlty of the room thermostat.

For I may employ in connection with my liquid fuel burning apparatus, the-fuel system disclosed in 'Patent 2,247,689, dated July 1, 1941; and I have shown a part of such a system associated with the apparatus in Fi'g`. 1. Communicating with the. bowl through the pipe 35 is an'outlet compartment 10 of a vessel 1|. Said outletcompartment is set off from a reservoir part 12 by a barrier or partition `13.- Liquid fuel is supplied to the reservoir part 12 through a pipe 15 from means (not shown),- such as` a float chamber, that serves to maintain aliquid level in the reservoir part 12 at about the elevation indicated by the broken line a. The float chamber,

as well as the `automatic control system presently to be referred to but not illustrated herein, are fully disclosed in the patent aforesaid. f

Pivotally supported above the barrier or partition 13 are trough-like buckets or dippers16, 11 and 18,-the same being arranged to dip into the fuel supply in the reservoir part 12 and transfer a quantity of the fuel to the outletcompartment 10 as the buckets are oscillated;r The mechanism by which such action is imparted to the `buckets or clippers comprises a gear that is rotatably i supported on a stub shaft 8| that projects from the adjacent upwardly extended side wall of the vessel 1|. Said gear carries a crank pin 82 that is connected, through a link 83', with the bucket 16. The gear 80 meshes with and is driven by a pinion 85 on a shaft 86 which, as disclosed in the aforesaid patent, is the shaft of a smallelectric motor that is attached to the side ofthe vessel 1|. Mounted on theshaft 88 beyond the pinion 85 is a double crank 81, the diametrically opposed.

pins of which are designated 88 and 89. These respective crank pins extend freely through slots in links 90 and 9|, the former being attached to the dipper or bucket 11,-and thelatter to the dipper or bucket 18.

Secured to and depending `from an` overhanging portion 92 of the upwardly extended end wall of the Vessel 1| are latch members 93 and 94 for holding engagement, respectively-with rearward extensions of the clippers or buckets 11 and 18, respectively. The latch membersr 93 and 94 are actuated lby the automatic control system i1lustrated -and described in the .beforementioned patent.

To describe, brieny, the operation of the fuel feeding means,` it may be said that the shaft 86, and consequently the pinion 85 and gear 80., are constantly driven `by the motor (not shown) By reason of its connection, through thelink 83 and crank pin 82 with thegear 80, the bucket 18 is constantly actuated. to, intermittentlytransfer quantitiesY of fuel-from the reservoir` parts 12 of the vessel 1| to the outlet compartment 10 vfrom whencethe liquid fuel ows to the burner bowl through the pipe 35, it being obvious that a quant-ity of fuel .would be present inthe outle'tcompartment to an -elevation'at least as highas'the outlet of the .pipe 35. Y ficient fuel ,is fed. to the burnerbowl to sustain low or pilotre.- -As long asnothing higher than', pilot fire is required, the clippers or buckets 11.

andk 18 Yare held-inactive-thatis, in elevatedposition,x bythe latch members l9,3 and 94the crank pinsV 88 and 89 lidling withintheslots ofthe respectiveimks an and .9| asthe dodbiecrlank e1 rotates., .Whenconditioris-are such that intermediate -fire is required-in order tom'aintain va given .temperature at the' roomthermostat, the system functions'inthemannerdescribed-in said patent toretra'ct 'latch member 93,therebyto fThus,4 atv all. times, `suf- 3 release the dipper or .bucket 11 and throw it into action through `its 'driving connection. with the dou-ble crank a1. 'shows the demand for heatv exceed the output of the burner at intermediate re, the latch member 94 will be retracted so as to release the dipper or bucket 18 to the -`action of the 4crank 'mechanism and `cause it to increase the amount of fuel fed to theA burner suiiciently As'the demand for heat` trated in Figs. `3and 4, where the element is designated generally by the reference numeral 95.

The upstandingwall 96 thereof is provided with a series 'of perforations or openings 91, 'which may correspond in size and spacing to the .perforations or openings 41 ofthe previously described form ofthe element. In the present case, two series of openings are made in the generally 4upwardly and outwardly extending portion 98,`

one such series being composed of `perforations or openings 99,- thatmay/be slightly larger` than the perforations or openings 91 of the previous series, While the second and outer `series of said portion 98 is composed of perforations or`open ings-'|00 that may be still larger than thosein the second mentionedl series. Here, again, the

aggregate area or capacity. of the' perforations or' openings in the generally upwardly and outwardly extending portion of vthe element is materially greater than that of the perforations or openings in the upstanding wall that defines the throat of the burner.

Figs. 5 and 6 vrather diagrammatically illustrate an embodiment `of the invention wherein the inner edge of the top wall |05 of the burner bowl |06 is connected, through a necklike structure designated generally by the reference numeral |01, with the annular bottom wall |08 `of the combustion chamber ||0, the peripheral wall of the bowl |06 being provided with primary air holes |09.' The combustion chamber 0 is enclosed within 4the upper portion of a cylindrical drum whose lower endis extended well below the bottom lwall |08 of said chamber and beyond the bottom of the burner bowl where it is closed by a circular plate H3. This plate is tted into the lower end ofysaid drum and defines vthe bottom of an air ycompartment I4 that surrounds the burner bowl and is' provided, in said plate ||3, with anopening ||5 through which said' -1 an air supply compartment Acommunicates with duct ||8.'A baille plate ||1 is supported by brackets ||8 above the opening ||5 to shieldr the burner bowl from the chilling effect of incoming air. Liquidfuel is supplied tothe burnerA bowl throughA a Ipipe f 'I'he previously mentioned neck-like 'structure |01 consistsof .an upstanding wall` |20 that defines the throatof'theburner, and a generally outwardlyand upwardlyextending stepped por# tion that merges with the bottom wall |08 ofthe f combustionchamber, such part being designated `Theiupstanding wall .|20 is provided with. a series' of ,perforations or .openings |22, while the upwardly 'and outwardlyextending portion |2| is provided` with seriesv of openings |23 that Hare arranged-to `direct air upwardly into the com.. t bustion chamber,`

Asin the former cases, the aggregate area or capacity of the-openingsgin the. generally up- .f

tional fact that air is supplied to the compartment 50 through the duct 56, as by forced draft means, if desired, air is constantly entering in limited quantity through the primary air holes l0, Ii and I2, in the peripheral wall of the burner bowl and through the openings 32 of the air distributor 3l, and in much greater amount through/the series of perforations or openings of the structural part or element 42 that con.`

stitutes` the neck of the burner. It may be pointed out, also, that the natural draft of the ue varies directly in accordance with changes in its temperature so that the draft is greater at high re than at low; and when forced draft means are provided for impelling air through the A duct 56 and compartment 50, the action of such means is usually accelerated as the fire increases. However, because the aggregate area or capacity of the perforations or openings 41 in the upstanding wall 46 of the element 42 is very considerably less than that of the perforations'or openings in the outwardly and upwardly extending portion 45 of said element, the volume and force of the air that enters through the former series is very much less thanthe volume and force of the air entering through the latter series.

In considering the operation of the apparatus, it will be' assumed that fuel is being fed to the burner bowl, at a rate to sustain operation at low or pilot fire, as by the action of the dipper or bucket 16, exclusively. With the fuel ignitedwhich may be accomplished by removing the plug from the opening i5 and introducing suitable igniting means therethrough after which the plug is replaced and the opening tightly sealed in the manner previously described-vapors are generated within the bowl and rise therein and mix with the air admitted through the primary air holes I0, Il and I2 and with the air issuing from the holes 32. of the air distributor 3|, thus being' conditioned for combustion when it reaches the curtain of air within the throat defined by the upstanding 'wall 46. Ample secondary air being thus added to the mixture, it completely burns and presents the appearance of a rather blue sheet of iiame extending horizontally across the throat in slightly spaced relation to the upstanding wall 46. The perforations or openings in said upstanding Wall are spaced closely enough together-to cause the streams or jets of air issuing therefrom to merge a short distance inwardly from said wall. This action, I nd, is much superior to that produced by a continuous `slot in that it effects a thorough mixing of the air and vapors immediately adjacent said upstanding wallwhereas, with a slot, the continuous sheet of air issuing therefrom has a tendency to obstruct, rather than to effectively mix with, the `vapors. The air in excess of thatrequired for producing complete combustion and maintaining the gentle curtain across the `throat at pilot fire, issues through the series of perforations or openings in the outwardly and upwardly extending portion of the'element 42 into the combustion chamber B0.

When, because higher fire is required, additional fuel is fed to the burner bowl, as through the action of either or both of the dippers or buckets 11 and 18, the volume of vapors generated in 'the bowl will increase to such an extent that the air entering through the primary air holes l0, Il and I2 and through the holes 32 of the air distributor will be only a small percentage of that required to mix with and convert th epesent quantity of vapors into a combustible gas. The deficiency in the primary air supplied through said holes, under the present conditions, will be compensated for by the air entering across the throat of the burner through the perforations or openings 41. In other words, when the increased volume of vapors reaches the throat of the burner it is rendered combustible by the addition of further primary air thereto and burns as .it enters the atmosphere of secondary air admitted to the combustion chamber through the perforations oropenings in the outwardly and upwardly extending portion of the element 42.

When' the apparatus is in operation and changes from low to higher fire, I have observed that the increased volume of vapors forces the curtain of flame that extends substantially horizontally across the throat of the burner at low fire upwardly and back, the flame assuming the effect of a rising column as the fire increases. The foregoing action of the flame is enhanced by the increased amount of air issuing through the openings 32 of the. air distributor 3|, caused by the acceleration of the flue draft, or such plus the increase in the air supply through the duct 56, as hereinbefore pointed out. The quantity of air entering through the primary air holes and through the perforations or openings in the element 42 is likewise increased, the amount of secondary air entering through the perforations or openings 48 in the outwardly and upwardly extending part of said element being ample to insure practically complete combustion under the higher fire conditions.

Furthermore, because combustion is confined to the region of the burner throat at low fire, and thereabove at higher fires, the bottom portion of the bowl never becomes injuriously hot.

From the foregoing, the operation of an anparatus' involving the modified form of neck structure illustrated in Figs. 3 and 4, and that of the modied form of the invention illustrated in Figs. 5 and 6, will be readily understood.

Having thus described my invention, what I claim is:

l. Liquid fuel burning apparatus of the class used for house heating or like purposes, the same comprising a combustion chamber, a burner bowl situated below said chamber, a structure in the form of a short wide neck through which the bowl and chamber communicate, thesame including an upstanding part of slight vertical extent adjacent the bowl and a part that extends generally outwardly and upwardly therefrom to where it joins the bottom of the combustionl chamber, the upstanding part being provided' with relatively small closely spaced perforations throughout the circumference thereof and the outwardly and upwardly extending part having closely spaced perforations throughout its circumference and whose aggregate capacity is materially greater than that of the perforations in said upstanding part, the

rst mentioned perforations serving to admit a limited amount of air from a surrounding air desarro space horizontally inwardly across the throat and the second mentioned perforations serving to admit air from said space in considerably greater amount generally upwardly into the combustion chamber, the bowl being provided with openings about its peripheral wall for admitting air from the aforesaid space to the bowl in comparatively small amount, and means for delivering liquid fuel to the bowl in varying quantities for producing low and relatively higher res.

2. Liquid fuel burning apparatus ofthe class used for house heating or like purposes. the same comprising a combustion chamber having a bottom wall provided with a relatively large opening, a burner bowl having a top wall spaced below said Cil A 5 conical part serving to admit additional air relatively greater amount upwardly and inwardly into the combustion cham-ber, the bowl being provided with openings about its peripheral wall for admitting air from the aforesaid space in comparatively small amount, and means for delivering liquid fuel to the bowl in variable quantity for producing low and relatively higher res d. .Liquid fuel burning apparatus of the class used for house heating or like purposes, the

'same comprising a combustion chamber, a

bottom wall and provided with an opening materially smaller than the beforementioned opening and in substantially axial alignment therewith, an element in the nature of a relatively thin short wall connecting the edges of said top and bottom walls about said openings and having an upstand'mg part adjacent the top wall of the burner bowl and a part extending generally outwardly and upwardly thereabove, the upstanding part being provided with a series of relatively small closely spaced perforations throughout its circumference and the outwardly and upwardly extending part also having closely spaced perforations throughout its circumference and whose aggregate capacity is several times that of the perforations of the upstanding part, the periorations of said upstanding part serving to admit a limited amount of air from a surrounding air space horizontally inwardly across the throat defined by said part and, due to the Aclose spacing of said perforations, to cause the air iets produced by said perforations to merge a short distance inwardly of said upstanding part into a continuous sheet throughout the central region of the throat, the perforations of the outwardly and upwardly extending part serving to admit additional air in relatively greater amount generally upwardly into the combustion chamber, the bowl being provided with openings about its peripheral wall for admitting air from the aforesaid air space in comparatively small amount, and means for delivering liquid fuel to the bowl in variable quantity for producing relatively low and higher hres.

3. Liquidfuel burning apparatus of'the class used for house heating or like purposes,l the same comprising a combustion chamber having a bottom wall provided with a relatively large circular opening, a lburner bowl having a top Wall spaced below said bottom wall and provided with a circular opening materially smaller than the beforementioned opening and in substantial axial alignment therewith, an annular element in the nature of a relatively thin short Wall connecting the edges of said top and bottom walls about said openings and having an upstanding partadjacent the top wall of the burner bowl and a frusto-conical part flaring outwardly and upwardly therefrom, the upstanding and frustoconical parts of said element being provided each with a series of closely spaced perforations throughout the circumference of the element, the aggregate capacity of the perforations of said upstanding part being materially less than that of the perforations of the frusto-'conical part, 'said series of perioratioiisL of the upstanding part vserving to admit a limited amount of air from a surrounding air space horizontally inwardly across the throat dened by said part, and the perforations of the frustoltends generally outwardly burner bowl situated below structure' in the form of a through which said chamber, a short wide neck the bowl and chamber communicate, the same including an opstanding part of slight vertical extent deiining a throatimmediately adjacent the bowl and a part that ex= from to where it joins the bottom 0f the combustlon chamber, the upstanding part being provided wlth series of relatively small closely spaced perforations throughout the circumference thereof andthe outwardly and upwardly extending part having a plurality of series of closely spaced perforations throughout its circumference, the holes of the diierent series becoming larger as the series progresses outwardly, the aggregate capacity of the perforations in the outwardly and upwardly extending part being several times greater than that of the periorations in the upstanding part, the rst mentioned series of periorations serving to admit a limited amount ci air from a surrounding air space horizontally inwardly across the throat. and the other series of perforations serving to admit air from said space in considerably greater amount generally upwardly into the combustion chamber, the bowl being provided with openings about its peripheral wall for admitting air from the aforesaid space to the bowl in comparatively small amount, and means for de-v livering liquid fuel to the bowl in varying quantities. for producing low and relatively higher hres. l

5. Liquid fuel burning apparatus of the class used for house heating or like purposes, the same comprising a combustion chamber having a 'bottom wall provided with a relatively large circular having a top wall spaced below said bottom wall and provided with a circular opening materially smaller than the beforementioned opening and in substantial axial alignment therewith, an annularl element in the nature of a relatively thin short wall connecting the edges of said top .and bottom ywalls about said openings and having an upstanding part adjacent the top wall of the burner bowl and a frusta-conical part daring outwardly and up= wardly therefrom, the upstanding part being provided with a series of closely spaced perforations throughout its circumference, and the frusta-conical part having an inner and an outer series of closely spaced perforations throughout the circumference of the element, the aggregate capacity of the perforations of said upstanding part being materially less than that of the perforations of the frusto-conical part, the bowl being provided with openings about its peripheral wall, and means for delivering liquid fuel to the bowl in variable quantity for producing low and relatively higher res.

6. Liquid fuel burning apparatus of the class used for house heating or like purposes. the same comprising a combustion chamber, a burner and upwardly thereence thereof and said horizontal portions of the steps being provided with closely spaced perforations thereabout. the aggregate capacity of the perforations of said horizontal portions being materially greater than that of the perforations in said upstanding part, and means for delivering liquid fuel to the bowl in varying quantlixtieess for producing low and relatively higher THEODORE B. FOCKE. 

